SPC Jun 3, 2025 0600 UTC Day 1 Convective Outlook

SPC 1200Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1236 AM CDT Tue Jun 03 2025

Valid 031200Z - 041200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS GREAT PLAINS TO
THE MIDWEST...

...SUMMARY...
Scattered severe thunderstorms are possible from the southern Great
Plains to the Midwest. Damaging winds and large hail are the primary
concern.

...Great Plains to the Midwest...

Large-scale pattern is not forecast to change appreciably during the
day1 period with upper troughing forecast to persist across the
northern Plains as a secondary upper low digs into the southwestern
U.S. by 04/12z. Even so, the progression of a notable short-wave
trough into the central Plains by afternoon will encourage a
seasonally strong cold front to surge south across the Great Plains.
By early evening, the frontal position should extend across central
WI-central MO-central OK-TX South Plains. This boundary will serve
as the primary focus for robust convection through the period,
especially during the afternoon/evening.

Early this morning, a considerable amount of convection has evolved
across the central Plains along the aforementioned cold front.
Latest radar data supports 00z model guidance, and substantial
thunderstorm clusters should be ongoing at the start of the period
from eastern KS into IA, as the LLJ will be focused into this region
of the Plains. While some of this activity may be locally severe,
the primary concern for severe is later in the afternoon as the
boundary layer warms/destabilizes.

Strongest boundary-layer heating is forecast across the southern
High Plains from eastern NM into western OK; although, a narrow zone
of modest heating is expected ahead of the front into central IL.
This corridor is where the strongest destabilization will occur,
with upwards of 3000 J/kg SBCAPE possible. Forecast soundings
suggest convective temperatures will be breached fairly early, as
700mb temperatures are not that warm along the front. While
mid-level temperatures/lapse rates are not particularly noteworthy,
high PW air mass and a convergent surface front, coupled with
large-scale support aloft, favor a convectively-active day. By late
afternoon, widespread convection may be noted along/ahead of the
front, and this zone should gradually sag south and east into the
overnight hours. Wind and hail are the primary concerns with
clusters and line segments that develop. While some supercell risk
will be noted, especially early in the convective cycle, storm
mergers and clustering should dominate.

..Darrow/Wendt.. 06/03/2025

StormPrep